In general, a mobile communication BS is installed in a service area requiring an appropriate antenna according to a network design and the vertical up/down tilt and the horizontal sector directional angle of a beam are appropriately set.
In order to adapt the installed antenna to the propagation environment of the site, a so-called Diagnostic Monitor (DM) test is carried out by measuring reception sensitivity across an actual overall service area and the vertical up/down tilting angle and horizontal sector directional angle of the antenna are optimized according to the DM test result.
Also, the down tilting angle and horizontal sector directional angle of the antenna are re-adjusted periodically according to a change in the subscriber distribution of the site, while continuing to monitor operation results.
However, it occurs in a real site environment that the inclination of a mast to which the antenna is installed changes due to external factors including storm or a clamp that ties the antenna to the mast is distorted horizontally. As a result, the antenna does not operate in an optimal manner, thereby making a reliable call service impossible.
Although this case is not caused by a technological defect in equipment, a remote control center cannot identify the cause. Thus to overcome the problem, the statuses of installed antennas are checked and cause analysis, readjustment, and optimization are performed for all sites.
Recently, mobile communication service providers mostly manage many sites by small personnel. That's why they cannot take an immediate action against problems in their sites, causing a high cost in a long term.
Moreover, the distance between a remote control center and a BS is not less than several hundreds of kilometers in some countries, thereby incurring a higher cost and taking a longer time in overshooting troubles.